The invention relates to a machine for distributing granular or powdered material in rows, which has furrow openers provided with outlet orifices for the material that is to be spread, at least some of said furrow openers being equipped with furrow closers mounted for pivoting in a vertical plane, said furrow closers consisting of supports with hillers provided thereon. The invention is addressed to the problem of enabling the hillers to be adapted to particular seed bed and soil conditions, thereby substantially improving their operation.
German Pat. No. 1,215,985 discloses a machine of the abovedescribed type of construction. This machine has been in practical use for some time. It suffers, however, from the disadvantage that the closing of the seed furrows is poor, especially in heavy soils and rough seed beds, because the hillers do not penetrate deeply enough into the soil and the bearing surfaces of the supports drag clods along with them and this greatly interferes with the furrow closing action. In light soils and in seed beds which are not clean, however, couch grass and other plant trash may be caught on the hillers and on the bearing surface of the supports, thereby pulling the seeds back out of the seed furrows. The wear and tear that is inevitable in the course of time makes the partially unsatisfactory operation described above still worse.
On account of these disadvantages it has proven indispensable under many conditions of operation to equip the machine additionally with seed drags. This, however, again entails the disadvantages that the teeth of the seed drag have to be additionally adjusted in the event of a change of the type of seed and row width, that the solid seed drag cannot adapt to the soil as well as individual prongs can so that the poor operation of the preceding hillers on the supports cannot always be improved as desired, that the drag increases the load on the machine on account of the way in which it is attached to it at a necessarily great distance to the rear of it, and finally this places the center of gravity of the machine, in the case of tractor-mounted machines, toward the rear, so that greater power must be expended in order to lift the machine.